1. Field of the Invention
The present invention relates generally to a track member for use in a track arrangement of a power driven overhead conveyor apparatus, the track member including an upper enclosing support portion for trolley members conveyed by the apparatus, and an integral lower chain enclosure for a driving chain of the apparatus.
More particularly, the track member in accordance with the present invention forms a part of a generally horizontal continuous overhead track formed by longitudinally joining a plurality of the track members. The overhead track formed with the track member constructed in accordance with the invention includes a continuous trolley member enclosing support portion having an integral downwardly-depending chain enclosure within which there is disposed a continuous driving chain of the overhead conveyor apparatus.
The term "chain enclosure" as used herein with respect to the present invention is intended to mean a structure which at least partially surrounds, but does not contact, any movable at least partially surrounded component.
The term "adjacent" as used herein with respect to the present invention is intended to mean nearby, but not contiguous.
2. Description of Relevant Art
There is known a general type of overhead trolley conveyor apparatus which employs a plurality of load-carrying trolley members which ride on an overhead track of the apparatus to convey materials from one point to another. Such an apparatus generally comprises a continuous loop overhead single track arrangement which is substantially horizontal with horizontal curves, and which may also include vertical curves if it is desired to convey material up or down from one level to another. A plurality of trolley members, each adapted to convey an individual load, ride along the overhead track arrangement of the apparatus. An exemplary trolley member construction comprises a pair of wheels, each mounted via wheel bearings to opposite ends of a horizontal shaft, with the wheels being adapted to ride along a horizontal surface of a track arrangement. The trolley member also includes, for example, a bracket affixed to the horizontal shaft, from which depends a load attachment member. A continuous chain is linked to each trolley member so as to convey the trolley members and their respective loads along the track, the chain being driven, for example, by a caterpiller drive unit. Such an overhead conveyor apparatus may be used to transport materials such as toys, electronic components, business machines, automotive parts, bulky furniture, tools, and a wide variety of other products.
The overhead track system employed in the above-described conventional conveyor apparatus is generally formed of a plurality of longitudinally joined rails, which may be joined by welding or other means, and which are supported at spaced intervals with standard hanger members which are secured overhead. The track members employed for forming the track system may take one of a number of known forms, such as an I-beam configuration or a substantially enclosed track having a square tubular configuration with a lower longitudinally extending slot.
Some of the most serious disadvantages attendant known overhead conveyor apparatus of the above-described type are: build-up of dirt, dust, overspray, and other contaminant materials on conveyor chain and track; costly deterioration of bearing and chain lubricants; corrosive attack on conveyor chain, bearings and rail; breakdowns in electrostatic spray equipment; production stoppage due to conveyor breakdowns; excessive maintenance costs; breakdown of lubricants which chain and bearings are exposed to temperature extremes; drip damage to clean parts from lubricants required to maintain system; and the high noise level associated with operation of the apparatus. Such noise is generated in part by the trolleys as they ride along the track, and in part by the chain which drives the trolleys.
Further, because the trolley members and the continuous chain are exposed in whole or in part, there is a danger of serious injury to workers operating the conveyor apparatus, should they accidentally come into contact with the moving parts of the apparatus while it is in operation.
The known track member constructions described hereinabove have had little or no success in eliminating the aforesaid disadvantages attendant overhead conveyor apparatus, and there has developed a desideratum for a track system which will substantially eliminate the aforesaid disadvantages and decrease the noise level associated with overhead conveyor apparatus, as well as to decrease the possibiliity of danger to workers.
The following disclosures are illustrative of known conveying apparatus.
U.S. Pat. No. 3,308,768 issued in 1967 to Orwin entitled "CONVEYORS FOR CONVEYING GOODS" discloses a conveyor track arrangement which includes a trolley track, and a separate chain supporting track disposed above the trolley track. The chain support track has disposed therein an endless chain having dependent trolley driving dogs which engage a trolley driving bar attached to the trolley body. The trolley tracks include horizontal guide support surfaces for the trolley wheels, and are generally of cruciform cross-section.
U.S. Pat. No. 3,875,866 issued in 1975 to Mazuyer entitled "OVERHEAD TRACK ASSEMBLY" discloses a conveyor track arrangement which includes a pair of rails defining a downwardly open channel. The rails are supported by the block portions of hangers so as to define a track for trolleys which are pushed along the track, and the upwardly facing surface of the rails receive and guide thereon the wheels of the trolley. The load support portion of the trolley extends downwardly between vertical portions of the rails.
U.S. Pat. No. 3,916,797 issued in 1975 to Block et al entitled "POWER DRIVEN CONVEYOR" discloses a track arrangement for a conveyor which includes two spaced horizontal tracks having inwardly-extending pins which carry roller wheels for supporting and conveying pallets between the two tracks. The spaced tracks include a lateral access portion which receives therein a conveyor chain such that the chain is substantially confined within opposite horizontal wall portions of the access opening.
U.S. Pat. No. 3,965,823 issued in 1976 to Bardot entitled "CONVEYORS" discloses a track arrangement for an overhead conveyor. The track is formed by a pair of rails which are substantially U-shaped in cross section, or may have the lower horizontal leg of the U-shaped removed, and which includes a central T-shaped groove having a surface which guides a pair of guide rollers on the trolley. The rails are secured to a special support which serves as a chair for the rails. The upper horizontal legs of the rails serves as the guiding surfaces for the trolley wheels.
The aforesaid relevant art arrangements, however, have individually and collectively failed to provide any satisfactory solution to the above-discussed shortcomings and disadvantages attendant trolley conveyor apparatus of the overhead power chain-driven type.
The present invention provides an effective solution to the aforesaid problems attendant overhead power driven convey apparatus by providing a track member for forming an overhead track which substantially reduces the high noise level and possibility of injury to workers normally associated with overhead conveyor apparatus. An overhead track system formed with the track members according to the present invention ensures that the wheels of the trolley members, as well as the chain of the conveyor apparatus, are effectively covered, so as to control noise normally associated with the operation thereof, as well as to enhance safety so as to aid in complying with Federal (O.H.S.A.) safety regulations.